The "FIXED" function in Google Sheets is used to format a number with a specified number of decimal places and optional thousand separators. Here is the syntax:

FIXED(number, [numberofplaces], [suppress_separator])

number: The number you want to format.

numberofplaces (optional): The number of decimal places to display. If omitted, it defaults to 2.

suppress_separator (optional): A logical value (TRUE/FALSE) that determines whether to include a thousand separator.

If set to TRUE, the separator is suppressed. If omitted, it defaults to FALSE.

Here are a few examples to illustrate the usage:

=FIXED(123.456) will return "123.46" (defaulting to 2 decimal places).

=FIXED(123.456, 0) will return "123" (no decimal places).

=FIXED(1234567.89, 2, TRUE) will return "1234567.89" (no thousand separator).

The "FIXED" function is helpful when you want to control the number of decimal places and formatting options for displaying numbers in your Google Sheets.